title: Serologic identification of the human secondary B cell antigens. Correlations between function, genetics, and structure.
abstract: The secondary B cell (SB) antigens are polymorphic HLA-linked antigens on human B cells and macrophages that are identified by primed T cell responses but are genetically distinct from the HLA-DR, MB, and MT antigens. Serologic identification of the SB molecule, using the monoclonal antibody ILR1, now makes it possible to correlate the function of these determinants in human T cell recognition with an Ia-like molecular structure and a genetic locus that marks a new HLA subregion. Three lines of evidence indicate that the ILR1 molecule identifies an epitope on some alleles of the SB gene: (a) the polymorphism of ILR1 -reactivity in the population correlates with SB2 SB3; (b) T cell proliferative response to SB2 and SB3 are specifically inhibited by ILR1; and (c) ILR1 reactivity is exactly concordant with the expression of SB2 in a panel of HLA-deletion mutant lymphoblastoid cell line. Together with previous studies, these results indicate that the SB antigens are on Ia-like molecules. Furthermore, the serologic studies of HLA-deletion mutant cell lines demonstrate that there are two HLA regions centromeric to HLA-B controlling expression of Ia-like molecules: a region toward HLA-B that controls expression of HLA-DR, and a region toward GLO that controls expression of SB.
mesh_terms: D000911:Antibodies, Monoclonal; D001402:B-Lymphocytes / Q000276:immunology*; D002460:Cell Line; D002874:Chromosome Mapping; D005802:Genes, MHC Class II; D006681:HLA-D Antigens; D006684:HLA-DR Antigens; D015805:HLA-DR5 Antigen; D000949:Histocompatibility Antigens Class II / Q000235:genetics / Q000276:immunology*; D006801:Humans; D008285:Major Histocompatibility Complex; D009154:Mutation; D013601:T-Lymphocytes / Q000276:immunology
chemical_list: D000911:Antibodies, Monoclonal; D006681:HLA-D Antigens; D006684:HLA-DR Antigens; D015805:HLA-DR5 Antigen; D000949:Histocompatibility Antigens Class II